Delhi was the most polluted city in last five years in India, shows report

Delhi-NCR pollution: Delhi had the highest PM 2.5 levels in the country in the month of October in the last five years, according to a recent report. According to a report put out by the Indian climate-tech start-up Respirer Living Sciences, the air quality has severely deteriorated since 2021. Delhi's pollution levels hit the "severe" mark on Thursday for the first time this season, and was at 402 at 5 pm. At least 18 out of 37 monitoring stations in Delhi recorded Air Quality Index (AQI) in the "severe" category.

The report stated that Delhi, Mumbai, Hyderabad and Kolkata recorded higher PM 2.5 levels in October 2023 as compared to other years. Though Chennai's AQI saw a fall of over 23 per cent compared to a year ago.

The report, which is based on the analysis of air quality between 2019 and 2023, further said that while air pollution has increased in the country's four major cities, Delhi, Mumbai, Hyderabad and Kolkata. But the air quality has significantly improved in Lucknow and Patna.

The study analysed PM 2.5 concentrations between 2019 and 2023 in eight of India's major state capitals-- Delhi, Mumbai, Chennai, Kolkata, Bengaluru, Lucknow and Patna.

In October 2023, Central Pollution Control Board (CPCB) data showed Delhi's air quality in October was the worst since 2020. Meteorologists have attributed it to the lack of rain. The capital recorded an AQI of 210 in October, compared to 210 in October last year and 173 in October 2021, according to the Central Pollution Control Board (CPCB).

Mumbai saw a steady increase in October PM 2.5 levels from 2019 to 2023, which saw a crucial deterioration in air quality.

"In Mumbai, last month, pollution spiked by over 42 per cent compared to October a year ago. In earlier years, PM 2.5 shot up between 2019 and 2020 (by 54.2 per cent), fell slightly in 2021 (by 3 per cent) and 2022 (by 0.9 per cent)," the report said.

Kolkata's PM 2.5 fell between 2019 and 2020 by 26.8 per cent, went up in 2021 by 51.7 per cent, decreased in 2022 by 33.1 per cent and rose again in 2023 by 40.2 per cent.

The report further said that Lucknow and Patna's October PM 2.5 levels dropped between 2022 and 2023 due to various reasons.

It is to be noted that an AQI between 0-50 is considered "good", 51-100 "satisfactory", 101-200 "moderate", 201-300 "poor", 301-400 "very poor" and 401-500 "severe". An AQI above 500 falls in the "severe plus" category.

Also read: Delhi air pollution: Primary schools shut for 2 days, construction ban in place as capital chokes; top 10 points

Also read: World Cup 2023: No fireworks display in Delhi, Mumbai matches due to worsening air pollution, says BCCI